A houseplant that has lived in the same pot for years will eventually run out of room. The roots fill the pot, circle around the inside, and push out of the drainage hole, and the plant can no longer take up water and nutrients as it should. Repotting gives the roots new space and fresh soil, and most plants answer with fresh growth.
Below you will find how to tell that a plant is root-bound, the best time to move it, and a careful step-by-step method that I use for nearly every pot in my house.
Signs Your Plant Is Root-Bound
You do not have to guess. Look for these clues.
- Roots growing out of the drainage hole, or showing on top of the soil.
- Water that runs straight through the pot and out of the bottom, or soil that dries within a day or two.
- Slow or stopped growth during the growing season, or small new leaves.
- A pot that bulges, cracks, or is pushed upward by the root mass.
- A plant that tips over because it is bigger than its pot.
For a sure answer, slide the plant out of its pot. If you see a dense web of roots in the shape of the pot, with very little soil left, it is root-bound.
When to Repot and When to Wait
Spring and early summer are best, because the plant is starting to grow and recovers quickly. Winter is the time to leave plants alone, since they are resting.
Wait if the plant is in bloom, newly bought, or already stressed by pests or disease. A plant with soggy soil and rotting roots needs a different approach, which I describe in signs you are overwatering your houseplants.
Some plants do not mind being snug. Snake plants and peace lilies are fine with crowded roots for a while, and moving them too soon can slow flowering. If a plant is healthy and the roots are not escaping the pot, leave it.
What You Need
- A new pot with a drainage hole, one to two inches wider than the old one for small plants, and two to three inches wider for large ones.
- Fresh potting mix made for houseplants, or cactus mix for succulents.
- Newspaper or a tray to catch the mess.
- Clean scissors or pruning shears.
- Gloves, since the sap of some plants can irritate skin.
A general houseplant mix is right for most plants. If the mix feels heavy, stir in a handful of perlite or fine bark so water drains well. Succulents and snake plants prefer a gritty, fast-draining mix.
Do not jump to a pot much larger than the old one. A big pot holds a lot of wet soil that the roots cannot use, and that invites rot. If you are reusing an old pot, scrub it with soap and hot water first.
Step by Step
- Water the plant a day before. A moist root ball slides out more easily, and damp roots break less than dry ones.
- Spread newspaper, turn the pot on its side, and hold the base of the stem between your fingers. Squeeze or tap the pot, and slide the plant out. Do not pull hard on the stem. If it is stuck, run a knife around the inside edge of the pot.
- Look at the roots. Healthy roots are firm and pale. Cut away any that are dark, soft or mushy.
- Loosen the root ball. Tease the outer roots apart with your fingers. If they are wound tightly, make a few shallow cuts down the sides of the root ball so the roots grow outward and not in circles.
- Put a layer of fresh mix in the new pot. Set the plant in so the top of the root ball sits about an inch below the rim, which leaves room for watering.
- Fill around the sides with mix and press gently with your fingers. Do not pack it hard, because roots need air. Keep the stem at the same depth as before, never deeper.
- Water thoroughly until water runs out of the bottom, then let it drain. Top up with mix if the soil settles.
- Put the plant back in its usual light, but out of strong sun for about a week.
Skip fertilizer for several weeks. Fresh mix has food in it, and tender new roots can be burned by too much.
If You Do Not Want a Bigger Pot
A plant that is already large does not have to move up again and again. You can slide it out, shave an inch or so of root from the outside of the root ball, and return it to the same pot with fresh mix. Clumping plants such as snake plants, spider plants and peace lilies can instead be divided. Pull or cut the clump into two or three pieces, each with its own roots, and pot them separately. This gives you new plants to share.
What Can Go Wrong
A few troubles are common after a move, and most of them fix themselves with calm, steady care.
- Wilting for a few days. This is transplant shock, which is normal. Keep the light and temperature steady and do not water extra to cheer the plant up.
- Water running down the sides. If the old root ball dried out before repotting, water may not soak in. Stand the pot in a basin of lukewarm water for twenty minutes, then let it drain.
- Soggy soil. Fresh mix holds more water than old, compacted mix, so check the soil with your finger before each drink.
- Pets and children. Many common houseplants, such as pothos, philodendron and peace lily, can upset a cat or dog that chews them. Sweep up trimmed roots and leaves, and wash your hands after working.
Quick-Fire FAQ
How often should I repot a houseplant?
Fast growers may need a bigger pot every year or two. Slow growers such as snake plants can wait much longer. Let the roots tell you.
Should I put gravel at the bottom of the pot?
No. A layer of gravel does not improve drainage and can keep wet soil closer to the roots. A drainage hole and a good mix do the job.
Is terracotta better than plastic?
Terracotta dries faster, which helps if you tend to overwater. Plastic holds moisture longer, which suits plants that like even dampness.
Can I repot a plant that is blooming?
It is better to wait until the flowers fade. Repotting a plant in bloom often makes it drop the blossoms.
— Grandma Gigi
